public class SubstringBuffer
{
	public static void main(String[] args)
	{
		StringBuffer buf = new StringBuffer("This is a book");
		System.out.println("String: " + buf);
		System.out.println("charAt(10): " + buf.charAt(10));
		buf.setCharAt(10, 'c');
		System.out.println("setCharAt(10, 'c'): " + buf);
		System.out.println("deleteCharAt(10): " + buf.deleteCharAt(10));
		System.out.println("substring(10): " + buf.substring(10));
	}
}